How many Warrior of Light exist in story?

[Anonymoose]

It's not necessary to have the Echo to face a Primal. What is a necessity a strong will and mind.

To clarify: the weak-willed fall to primal influence faster; we've yet to see anyone who can hold out indefinitely (without the Echo). Recall the Sahagin quest where Maelstrom soldiers were tied up on grounds tainted by Leviathan's energies (where I assume he'd tempered people in the past). By the time you get there, some have been enthralled, some have not - but all would have been had you not arrived.

Speaking of Zurvan, you'd recall that several of the troops present fell to his influence, but others did not.

This, this would likely still be a time thing - being too close to the primal's energies for too long. Krile and Unukalhai both say that the Imperial soldiers have no means of resisting Zurvan's will for long, and when you arrive, they marvel that even half-asleep his aura is corrupting some of the legionnaires.

Strong willed individuals such as this likely composed the Company of Heroes, who I doubt all had the Echo.

I don't recall having confirmation that any of the ones we know had the Echo, really. (Though, if 1.0 had continued on its trajectory, we would have allied with them.) The Company of Heroes went into battle knowing each one might be their last, knowing they might have to be killed by their own men. Tempering was so inevitable that it was sometimes worked into their strategies: the first wave would run in and many would be tempered, the second wave would fight those corrupted from the first wave, and the third wave would attack the primal with those who were able before it could temper more people.

Those are likely most of your companions. <...> I believe our party members receive protection from Hydaelyn by virtue of association with us.

Based on how often the game uses terms like "Echo-blessed" and "Godless Blessed", etc. to refer to our party, I think it's implied that we met them through the Scions of the Seventh Dawn, which has many Echo-blessed warriors in its ranks due to Minfilia's side of the operation. If it was as simple as the Mothercrystal actively shielding people in the moment, there'd be no reason not to bring, say, Thancred or Y'shtola, right?